Ответ: UNTIL RECENTLY  THE PLANET WAS A LARGE WORLD IN WHICH PEOPLE AND NATURE WERE IN BALANCE. THE PEOPLE DIDN’T  POLLUTE NATURE. BUT NOWADAYS , ENVIRONMENTAL PROBLEMS ARE THE MOST IMPORTANT FOR US. IN MY CITY  THERE ARE  ENVIRONMENTAL PROBLEMS TOO . PEOPLE CUT DOWN TREES, DESTROY ANIMALS ,  AND , OF COURSE, THERE ARE PLANTS AND  FACTORIES . EVERY PERSON  MUST NOT THROW A RUBBISH IN STREET. THEY MUST NOT DESTROY ANIMALS AND PLANTS. THEY  MUST GROW  A MORE TREES, BECAUSE THEY MAY CLEAN OUR AIR